neuronstagingarea.js: fix automatic color assignment.

Colors could be repeated if a skeleton was removed and then another added.
Neuronstagingarea.js: remove unused function.
connectivity: fix incorrect function name.
neuronstagingarea.js: fix removal of skeletons from Selection Table.

The cached array indices were not updated correctly.
neuronstagingarea.js: rename local variable to avoid confusion with member variable.
webglapp.js: Fix asynchronous issue

When loading a skeleton into the 3d view, this takes some time,
and during this time the skeleton may have been removed from the selection,
and therefore upon receiving the json with the skeleton data, this must
be ignored.
Merge branch 'master' of github.com:acardona/CATMAID